基于流气式测量原理,自行研究开发了土壤氡析出率连续测量装置,并在北京西北地区开展了为期24天的现场连续测量。野外现场实测证实:研发的土壤氡析出率连续测量装置满足现场连续测量需求。氡析出率连续测量结果表明:降雨对土壤氡析出率有显著影响。降雨过程中,氡析出率会明显上升,且氡析出率上升的幅度随着降雨量的增加而增加;无降雨情况下,土壤氡析出率呈现明显的日变化规律,造成此现象的主要原因在于土壤湿度的周期性变化。
It is very important to measure radon exhalation rate from soil continuously for a better evaluation on the source of radon and its level, environmental radon exposure, and uranium tailings processing. Continuous measurement on radon exhalation rate of soil was studied theoretically and practically. As the result, a device was developed on basis of the flow air method, and a 24 days field continuous measurement was carried out in the northwest of Beijing with the device developed during spring 2012. It was indicated by the experimental results that rainfall has obvious effect on radon exhalation rate from soil. In the process of rainfall, radon exhalation rate increased apparently, and the increment of radon exhalation rate heightened with the rise of precipitation. For days of no rain, the radon exhalation rate from soil presented diurnal variation, and the diurnal periodical change of soil humidity was considered to he the main cause of this phenomenon.